Where do the 4Cs of diamond grading come from?

When you purchase a diamond it’s important to know that each gemstone has its own unique set of features and qualities; these aspects contribute to the value of a diamond. But how can a potential buyer establish the value of a diamond in a fair and accurate way, before buying the gemstone? Before the 20th century there was no standard process in which a diamond was graded, especially when it came to the quality and cut. Fortunately, during the middle of the twentieth century GIA (Gemological Institute of America) developed an official diamond grading system called the 4Cs of Diamond Quality: Colour, Clarity, Cut and Carat Weight. Today, the 4Cs are used globally to establish the value of each unique diamond.

HISTORY OF DIAMOND GRADING PROCESS BEFORE THE GIA INTRODUCED THE 4Cs

The GIA system was created to avoid confusion during the international diamond trading process

Before the GIA created the 4Cs of Diamond Grading various other methods were used to record the colour of a diamond during the Kimberley diamond rush. For example, diamond graders used multiple A’s to describe a colourless diamond (e.g.: AAA, AA, A) while others used numbers (e.g.:1,2,3), Roman numerals (e.g.: I, II, III, IV) or a brief description of the gem-quality (e.g.: blue white, fine white).

Even though these multiple colour grading methods worked perfectly amongst local traders, the difficulty came in when diamonds were traded internationally; in many cases diamond graders across the world used different types of grading systems. This reason alone made it difficult to get the accurate value of a certain diamond before it was purchased.

To standardise diamond grading, the GIA created a universal diamond grading system to describe diamonds in order to avoid unnecessary confusion. A modern-day colour scale, starting at the letter D, was then put in place to make sure a diamond’s value and colour was rated accordingly.

THE 4Cs OF DIAMOND GRADING

The 4Cs of Diamond Quality is a universal grading scale which determines the quality of a diamond

With the 4Cs of Diamond Quality in place, a universal grading scale has been established to determine the quality of a diamond. By looking at these factors any diamond grader would be able to determine the value of a diamond according to the regulated system. But what exactly does the 4Cs of Diamond Quality entail?

CUT OF A DIAMOND

The cut of a diamond is the only part of the grading process that is influenced by the handiwork of a craftsman

During the cutting process the shape of a diamond as well as the proportions of the facets will be determined. With the correct cutting procedures light will enter the stone and reflect from the top of the table; this in return will give the diamond that sparkle effect. To achieve this type of quality in a diamond, the facets need to be cut and polished to the correct proportion and symmetry in order to maximise the fire, brilliance and scintillation of the diamond; this includes the crown, culet, table, girdle and pavilion of a diamond. The cutting process of the 4Cs is the only aspect of the stone that is influenced by the handiwork of a craftsman. Even though, the cutting process is determined by the human hand it remains one of the most important grading factors of a diamond. Therefore, a diamond with a better cut will be valued a lot higher than a diamond with a higher carat weight.

CARAT WEIGHT OF A DIAMOND

The carat of a diamond is determined by the weight and not the shape of the gemstone

The carat of a diamond is determined by the weight and not the shape of the gemstone; in this case a one carat diamond is an estimated 200 milligrams. During the grading process a jeweller will establish the carat weight of a diamond by subdividing the gemstone into 100 points. For example, instead of referring to a 0.25 carat diamond a jeweller will refer to the stone as a 25 pointer. A one carat diamond is more valuable than a half a carat diamond, considering that the stone has been cut correctly. Even though the weight of the diamond plays a big part in the grading process, the other qualities of the diamond should also be considered.

COLOUR OF A DIAMOND

The colour of a diamond is determined by a grading scale that starts from D to Z

The most popular diamond used during the jewellery making process is colourless; a colourless diamond ranges from a truly colourless gemstone to a hint of a light yellow or champagne colour diamond. But how exactly do graders determine the colour of a diamond? A diamond’s colour is determined according to a grading scale from D (colourless) to Z (yellow). The process is considered to be done under very strict condition since the shading of a colourless diamond isn’t always visible to the naked eye. Graders will use a master diamond sample set to compare the diamond’s different shades accordingly. Rare diamonds can also be found in nature; these stones are extremely valuable and come in shades of red, blue, yellow, pink, black, green and orange. These diamonds are graded according to the intensity of the colour.

CLARITY OF A DIAMOND

The clarity of a diamond is established by the absence of blemishes and illusions

The clarity of a diamond is established by the presence of blemishes and inclusions in a diamond. During the formation process, the diamond’s internal qualities and characteristics will usually be affected by a number of blemishes and inclusions. Even though a diamond will never be completely without any blemishes and inclusions, the closer it gets, the more valuable the diamond becomes. Inclusions in a diamond are unique to each stone, serving as its fingerprint from nature.

When it comes to purchasing a diamond it’s important to consider the 4Cs of Diamond Quality. This will help you as a buyer to determine the quality and value of the unique diamond. The 4Cs is also the best standard guideline to follow if you’re looking to purchase the best quality diamond in a specific price range.